1. Field of the Invention
The invention relates to a device and a method for checking and rotating electronic components, in particular flip chips, with a pivoting part attached to a pivotal point for rotating the electronic components, a first pickup element being fixed on the exterior of the part for picking up a single electronic component from a substrate and keeping hold of it during a rotational movement of the part.
2. Description of Related Art
For methods that are based on a flip chip principle, it is known that individual electronic component parts arranged in a sandwich separated from one another, such as semiconductor chips arranged in a wafer, the wafer in turn being set on an extensible carrier sheet, are picked up from this carrier sheet and rotated, i.e. turned upside down, in order to deposit them in the rotated position for the subsequent die bond or die sort. For this purpose, the single chip is first detached from the reverse side of the carrier sheet with a needle, the so-called die ejector, and transferred with a pickup element, such as a vacuum pipette, advanced from the front or from above. For this, the vacuum pipette is usually arranged as a flip tool on a flip head of a part pivoting about a pivotal point, and keeps hold of the selected chip during a 180° rotation of the pivoting part. After the 180° rotation has taken place, the chip turned round in this way is picked up by a pick-and-place element on its reverse side, in order then to transport the chip in this rotated situation to the desired position, for example within a smart card module.
In order to check the surface of the individual chip still arranged on the substrate for intactness before it is picked up, and at the same time to be able to check that it is in the correct position before it is picked up, a first optical facility, for example a camera, is arranged above the pivoting part for the inspection of the wafer. Since an optical connection line set up perpendicular to the surface of the wafer and the chip between the first optical facility and the wafer surface is important for an optimized check, the camera is arranged directly over the chip to be picked up. For this reason, the pivoting part must be rotated out of the perpendicularly running optical connection line each time before a chip is picked up, in order that a so-called wafer inspection can be performed.
This results in the following sequentially occurring method sequence for each flip chip: First, a check of the surface of the chip to be picked up must be performed using the camera. The flip head is then rotated into the optical connection line, in order to pick up the chip by its upper surface using the vacuum pipette attached to the flip head. By means of the pivoting part, whose rotational axis is arranged outside the optical connection line, the chip is now rotated through 180° in such a way that the flip head is now in a rotated position outside the optical connection line. A further check performed on the chip's position by means of a second optical facility in the form of a camera should supply data on a flip offset of the flipped chip. The flipped or rotated chip is then transferred to a placing facility in the form of a place head, and a correction is made to the flip offset based on transferred correction values.
Such a sequence of successive steps leads to a high time requirement for the overall process of checking and rotating a chip, and thereby reduces the throughput of the device. It therefore also results in higher operating costs.